For the past few days, I have been going through the book "Linux from Scratch" (the link is attached below). It was smooth sailing until the 8th chapter of the book when it was time to install the kernel and grub. I had a UEFI system, so I had to follow a modified list of instructions (which is also linked below). Upon reboot, I would be greeted by the grub screen, allot of text would run down the screen and then it would freeze on this error message...
VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6
I checked around on the internet, and found a few people with the same problem, but it seems like something hardware dependent with varying solutions. Listed on the book's website is a fax, with this same problem reported. It is shown below...
Kernel panic: VFS: unable to mount root fs
There are several reasons why the kernel might be unable to mountthe root filesystem.
- Did you specify the correct partition in /boot/grub/menu.lst?
- Is support for the hard drive enabled in the kernel. For SCSI this means support for the specific SCSI adapter.
- Is support for the hard drive compiled into the kernel, not just as a module. (Modules are stored on the filesystem. If a driver needed to access the filesystem is stored as a module on that filesystem, well ... you know ...
- Is support for the filesystem compiled into the kernel. Again, not a module. Support for ext2 is enabled by default, but others like ext3, reiser, jfs, and xfs are not.
I am fairly certain that I specified the correct partition. Below is output from lshw -class disk -class storage and my grub.cfg file (It is referred to menu.lst above, but that is for a different version of grub)
*-storage
description: SATA controller
product: Sunrise Point-H SATA Controller [AHCI mode]
vendor: Intel Corporation
physical id: 17
bus info: pci@0000:00:17.0
version: 31
width: 32 bits
clock: 66MHz
capabilities: storage msi pm ahci_1.0 bus_master cap_list
configuration: driver=ahci latency=0
resources: irq:318 memory:df430000-df431fff memory:df434000-df4340ff ioport:f090(size=8) ioport:f080(size=4) ioport:f060(size=32) memory:df43300
*-disk
description: ATA Disk
product: ST1000LM014-1EJ1
vendor: Seagate
physical id: 0.0.0
bus info: scsi@1:0.0.0
logical name: /dev/sda
version: DEMG
serial: W7735PQF
size: 931GiB (1TB)
capabilities: gpt-1.00 partitioned partitioned:gpt
configuration: ansiversion=5 guid=81486a44-3cdc-49e2-8b1b-e52c0a0596d6 logicalsectorsize=512 sectorsize=4096
# Begin /boot/grub/grub.cfg
set default=0
set timeout=5
insmod gzio
insmod part_gpt
insmod ext4
set root=(hd0,gpt4)
# hd[x] is the drive of the LFS partion and gpt[y] is the partition
insmod efi_gop
insmod efi_uga
insmod font
if loadfont /grub/unicode.pf2; then
loadfont /grub/unicode.pf2
set gfxmode=auto
insmod gfxterm
set gfxpayload=keep
terminal_output gfxterm
fi
menuentry "GNU/Linux, Linux 4.9.9-lfs-8.0" {
linux /boot/vmlinuz-4.9.9-lfs-8.0; root=/dev/sda4 ro
}
To address the 2nd through 4th points of the faq reply above, I tried numerous setups of the kernel. I followed the setup exactly as described in the hint linked below. I also tried copied .config file of my host system (an ubuntu 16.04 running on a 4.10 core), and I even tried enabling all options through the make allyesconfig command while disabling "support for uevent helper" (It was written in the book that this could cause errors if enabled). So far, no luck. Below is an excerpt of my .config file (it was far too large to put in this post)...
# Controllers with non-SFF native interface
#
CONFIG_SATA_AHCI=y
CONFIG_SATA_AHCI_PLATFORM=y
CONFIG_SATA_INIC162X=y
CONFIG_SATA_ACARD_AHCI=y
CONFIG_SATA_SIL24=y
CONFIG_ATA_SFF=y
#
# SFF controllers with custom DMA interface
#
# CONFIG_PDC_ADMA is not set
CONFIG_SATA_QSTOR=y
CONFIG_SATA_SX4=y
CONFIG_ATA_BMDMA=y
#
# SATA SFF controllers with BMDMA
#
CONFIG_ATA_PIIX=y
CONFIG_SATA_DWC=y
CONFIG_SATA_DWC_OLD_DMA=y
CONFIG_SATA_DWC_DEBUG=y
CONFIG_SATA_DWC_VDEBUG=y
CONFIG_SATA_MV=y
CONFIG_SATA_NV=y
CONFIG_SATA_PROMISE=y
CONFIG_SATA_SIL=y
CONFIG_SATA_SIS=y
CONFIG_SATA_SVW=y
CONFIG_SATA_ULI=y
CONFIG_SATA_VIA=y
CONFIG_SATA_VITESSE=y
Below are some more useful files, and the links discussed above. At this point, I have no idea how to precede at this point, so I am wide open to any suggestions.
http://www.linuxfromscratch.org/
http://www.linuxfromscratch.org/hint...s/lfs-uefi.txt
Here is my etc/fstab file. As you can see, the there is a uefi partition.
# Begin /etc/fstab
# file system mount-point type options dump fsck
# order
/dev/sda4 / ext4 defaults 1 1
/dev/sda3 swap swap pri=1 0 0
proc /proc proc nosuid,noexec,nodev 0 0
sysfs /sys sysfs nosuid,noexec,nodev 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
tmpfs /run tmpfs defaults 0 0
devtmpfs /dev devtmpfs mode=0755,nosuid 0 0
/dev/sda1 /boot/efi vfat defaults 0 1
efivarfs /sys/firmware/efi/efivars efivarfs defaults 0 1
# End /etc/fstab
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 81486A44-3CDC-49E2-8B1B-E52C0A0596D6
This is from the fdisk -l command. dev/sda4 is my LFS partition
Device Start End Sectors Size Type
/dev/sda1 2048 1050623 1048576 512M EFI System
/dev/sda2 1050624 1834608639 1833558016 874.3G Linux filesystem
/dev/sda3 1937008640 1953523711 16515072 7.9G Linux swap
/dev/sda4 1834608640 1937008639 102400000 48.8G Linux filesystem
I have a Dell Inspiron 15 7000 series laptop
